ErrorCollector: Ignore additionalProperties error if there are other violations

If there are other violations `additionalProperties` might be a false
positive. See opis/json-schema#148.

Author: Dominic Tubach

src/Errors/ErrorCollector.php

@@ -65,6 +65,13 @@ public function addError(ValidationError $error): void
             array_map(fn (ValidationError $subError) => $this->addError($subError), $error->subErrors());
         }
 
+        if ('additionalProperties' === $error->keyword() && $this->hasErrors()) {
+            // If there are other violations "additionalProperties" might be a
+            // false positive.
+            // See https://github.com/opis/json-schema/issues/148.
+            return;
+        }
+
         $path = $this->pathToString($error->data()->fullPath());
         if (isset($this->errors[$path])) {
             $this->errors[$path][] = $error;

tests/CollectErrorsTest.php

@@ -305,4 +305,40 @@ public function testIf(): void
         self::assertTrue($errorCollector->hasLeafErrorAt(['string']));
         self::assertSame(['/string'], array_keys($errorCollector->getLeafErrors()));
     }
+
+    /**
+     * An error for "additionalProperties" should not be added if there are
+     * other violations because of a possible false positive.
+     * See https://github.com/opis/json-schema/issues/148.
+     */
+    public function testAdditionalProperties(): void
+    {
+        $schema = <<<'JSON'
+
+            {
+                "type": "object",
+                "properties": {
+                    "boolean": { "type": "boolean" }
+                },
+                "additionalProperties": false
+            }
+            JSON;
+
+        $validator = new SystopiaValidator([], 10);
+
+        $errorCollector = new ErrorCollector();
+        $globals = ['errorCollector' => $errorCollector];
+        $validator->validate((object) ['boolean' => 123, 'foo' => 'bar'], $schema, $globals);
+        self::assertCount(1, $errorCollector->getLeafErrors());
+        self::assertTrue($errorCollector->hasLeafErrorAt('/boolean'));
+        self::assertErrorKeyword('type', $errorCollector->getLeafErrorsAt('/boolean')[0]);
+
+        // Test that "additionalProperties" error is added if there's no other violation.
+        $errorCollector = new ErrorCollector();
+        $globals = ['errorCollector' => $errorCollector];
+        $validator->validate((object) ['boolean' => true, 'foo' => 'bar'], $schema, $globals);
+        self::assertCount(1, $errorCollector->getLeafErrors());
+        self::assertTrue($errorCollector->hasLeafErrorAt('/'));
+        self::assertErrorKeyword('additionalProperties', $errorCollector->getLeafErrorsAt('/')[0]);
+    }
 }